The Forney 75325 Industrial Milton style 5-piece 1/4-inch plugs and coupler value pack is made of steel construction. These airline accessories from Forney are specifically designed for use on compressed air lines. Forney Industries is a family-owned metal working product company that has been in operation since 1932, making it one of the longest-running companies of its kind in America. With a wide range of over 5,000 products, Forney caters to the hardware, automotive, farm and ranch, and do-it-yourself markets. If you have any questions related to metal working, Forney is here to provide you with the answers you need. We are dedicated to ensuring your success, regardless of your location, size, or specific needs. The Industrial Milton style 5-piece value pack includes three 1/4-inch (6.35mm) male plugs, one 1/4-inch (6.35mm) female plug, and one 1/4-inch (6.35mm) female coupler. The maximum working pressure for this value pack is 300 PSI.